Conventionally, most domestic fabric softener compositions contain thickening agents that improve their rheology profile.
Standard cationic polymeric thickeners are crosslinked water swellable polymers, such as those disclosed in WO 90/12862 (BP Chemicals), which relates to the use of lightly (5-45 ppm) crosslinked cationic thickeners, or US 2002/0132749 (Colgate-Palmolive Company) and Research Disclosure 429116, which relate to the use of heavily crosslinked cationic thickeners.
EP 2 373 773 (SNF) provides effective polymeric thickener having anti redeposition benefits. These polymers give to fabric softener composition a good rheology profile combined with a good anti redeposition profile. According to this document, it is essential that the polymer be prepared by means of a reverse phase oil-in-water emulsion polymerization.
One of the main drawbacks of fabric softener compositions is the difficulty to disperse easily and rapidly the composition in water, specifically when they are viscous. Generally the dispersion of such compositions takes time and involves mechanical stirring.
Despite great improvements in terms of rheology profile and anti-redeposition benefits, the polymeric thickeners described in EP 2 373 773 do not give full satisfaction in terms of dispersability properties in water. More specifically, the softening compositions comprising these polymers do not disperse readily and efficiently in water.
The prior art has failed to provide effective thickener having adequate satisfaction regarding the problem of dispersion in water, and having a satisfactory viscosifying capacity.